Mental health expert on the importance of memory, and the causes of amnesia

After a man was found in Peterborough with no idea who he is or where he has come from, professor of mental health at the University of Nottingham Tom Dening explains why memory is so important to our identity.

Prof Tom Dening, from University of Nottingham's department of mental health
Prof Tom Dening, from University of Nottingham's department of mental health Credit: University of Nottingham

Memory is really important to us all.

It is one of the ways in which we know who we are, and how other people recognise us.

We all have lapses in our memory, and this is more likely if we are tired, stressed, unwell or distracted in any way.

Memory can be affected by various disorders affecting the brain.

The best known of these is dementia, where people’s ability to remember things (dates, events, names, etc) tends to get worse over time. However, dementia affects other aspects of mental functioning, such as language, thinking, practical skills, so it is more than just a memory problem.

When the problem is limited to a loss of memory, we use the word amnesia.

There are lots of causes of amnesia, for example having a head injury or being very drunk, but there are some less common causes that appear very puzzling.

How the brain stores memory
How the brain stores memory Credit: University of Texas

One is called transient global amnesia. This usually lasts less than 24 hours and people forget a lot of things but not who they are.

Another sort of amnesia is called psychogenic amnesia and this is said often to result from traumatic experiences, though in some cases the person may have good reasons for forgetting what has happened! They may turn out to be running away from a very difficult situation.

So when people are found who have no recollection even of their name, then doctors have to be very careful and try to get whatever background information that they can.

Many of these cases do resolve in the end with the right kind of support.